Radiator filler cap



Aug. 26, 1969 w. c. MITCHELL 3,463,346

RADIATOR FILLER CAP Filed July 26, 1968 l A 22 INVENTOR '7 WM m Colfon Mitchell 44 ATTORNEY United States Patent 3,463,346 RADIATOR FILLER CAP William Colton Mitchell, Cheshire, Conu., assignor to Scovill Manufacturing Company, Waterbury, Conn a corporation ofConuecticut.

Filed July 26, 1968, Ser. No. 747,886

Int. Cl. B65d 51/16 U.S. Cl. 220-44 Claims ABSTRACT OF THE DISCLOSURE A filler cap especially for sealed vehicle radiator systems in which the plug includes pressure release means and is itself held down in the radiator fill opening by a pair of stacked C-rings. The first of these can be readily removed permitting the plug to raise and vent pressure. The second C-ring can only be removed after the plug is pressed down in its opening so that the ring can be raised to clear removal blocking means on the plug.

This invention relates to a radiator filler cap for sealed automobile cooling systems. More specifically, this invention relates to a cap which incorporates pressureresponsive venting means and includes a fail-safe, lock-in device which precludes inadvertent removal of the cap when the system is under significant pressure.

The filler cap of the invention may also include automatic means for breaking the vacuum in the radiator should a vacuum develop.

Further features of the invention will be apparent from a reading of the following specification including the drawings wherein;

FIG. 1 is a sectional view of a filler cap embodying the invention;

FIG. 2 is a bottom plan view;

FIG. 3 is an exploded perspective view; and

FIGS. 4a, 4b and 4c are enlarged fragmentary views of progressive steps in the removal of the plug.

A filler cap embodying the invention is generally designated in FIG. 1. It comprises an outer annular housing 12 having an upper mouth 14 secured about the opening in the radiator R. The lower end of the housing 12 is formed with an inward lip 16 adapted to serve as a valve seat. As shown, the lip 16 may peak up in an annular seating ridge.

The housing is formed with a peripheral recess 18 which presents a downwardly inclined shoulder 20.

A hollow plug body 22 is formed with a central open- .ing 24 in its lower end. The plug about the margin of the opening is fitted with an annular gasket 26 of U-shape cross section as shown. Outward on the plug from the margin of the opening are an annularly arranged series of ports 28 through which venting may be accomplished during removal of the plug. The wall of the plug above the ports may be peripherally indented to hold a resilient O-ring 30 which sealingly engages the housing.

Adjacent its upper end, the plug is equipped with an overflow neck 32 to which a hose may be attached to direct the overflow downward.

As shown, the gasket 26 normally engages the valve seat 16. A closing plate 34 is disposed inside the plug and has, adjacent its margin, a downward rib 36 which normally engages the upper surface of the gasket 26 to close off the interior of the plug. A helical spring 38 is disposed within the plug and abuts the upper wall thereof. The lower end of the spring engages and yieldingly holds down the plate 34. To center the spring on the plate, an upward circular hump 40 is formed in the plate. It will be understood that the spring 38 serves to hold the opening 24 closed except on occurrence of high pressure I 3,463,346 Patented Aug. 26, 1969 ice within the radiator at which time the spring will yield permitting the plate 34 to raise above the gasket 26 to allow pressure to escape. A central opening in the plate mounts a conventional duckbill oneway check valve 42 permitting entrance of atmospheric air to break a vacuum should one be generated within the radiator.

As shown in FIG. 1, the plug is reducedin diameter at about the level of the peripheral recess 18. At this reduction, the plug presents an annular upward shoulder 44. Inward from the shoulder there is formed an annular upward step 46 which serves as a blocking means as will be understood.

Holding the plug in the housing in the embodiment shown are a pair of stacked C-shaped rings 48 and 50 disposed in the recess. The rings may be of the commercially available variety shown. The upper ring 50 engages and is held down by the downward shoulder 20 while the lower ring 48 engages the upward shoulder 44 on the plug.

It is important that the distance between the blocking means 46 and the downward projection of the mouth 14 be less than the width of the lower ring 48. By this arrangement, the plug cannot inadvertently be removed while there is substantial pressure still in the radiator. Referring to FIG. 4a, the lower C-ring 48 normally holds the plug down in place and is itself held down by the upper ring 50 which engages shoulder 20. In removal (FIG. 4b), the C-ring 50* is manipulated by a tool engaging the openings 50a (FIG. 3) and drawing the ends together. This contracts the ring. It is then lifted upwardly through mouth 14. Pressure in. the radiator will immediately drive up the plug the thickness of ring 50 so that ring 48 abuts the shoulder 20 (FIG. 4b). The raising of the plug will permit pressure to pass between the seat 16 and gasket 26, through the vent ports 28 into the body of the plug and out overflow 32. While this is taking place, the remaining ring 48 cannot be removed since the blocking means 46 will not permit its contracting enough to clear the mouth 14.

Upon depressurizing of the radiator, the plug 22 may then be pressed down (FIG. 4c) so that the ring 48 may be removed in a manner similar to the earlier removal of ring 50.

There is thus prevented the inadvertent removal of the plug while there is pressure in the radiator. At the same time, and in the embodiment shown, the filler cap of the invention permits a pressure relief through the raising of plate 34 against the spring 38 should the pressure become excessive. The cap also provides a vacuum breaking means 42.

While the invention has been shown in only one embodiment, it should be understood that it is not so limited but is capable of numerous changes and reasonable variations.

I claim:

1. A radiator filler cap for sealed vehicle cooling systems comprising an outer annular housing adapted to be secured in the radiator fill opening and having at its lower end an inward lip serving as a valve seat, the housing having about its inside surface a downward shoulder, a hollow plug body having an overflow means adjacent its upper end, and a central opening at the bottom thereof, the bottom normally abutting the seat to close the valve with the periphery of the plug above the bottom in sealing engagement with the inside of the ring, a closing plate inside the plug, spring means holding the plate down in closing relation with the opening, the plug presenting an upward shoulder spaced below the downward shoulder on the housing, blocking means formed on the plug in- Ward from the upward shoulder, and a pair of C-rings stacked one above the other in the recess, the upper one engaging the downward shoulder and the lower one engaging the upward shoulder, the dimensions of the lower C-ring being such that its upward movement is normally blocked by the upper C-ring and its contraction and removal is blocked by the blocking means except when the upper C-ring is removed and the lower C-ring is raised to the normal position of the upper C-ring and the plug is seated on the valve seat.

2. A radiator filler cap as described in claim 1 wherein the plug has passage means through its peripheral wall above the portion that engages the valve seat to permit venting of pressure through the overflow means as the plug is removed.

3. A radiator filler cap as described in claim 1 wherein the plate is provided with a central vent closed by a check valve permitting the breaking of vacuum in such 15 a radiator.

References Cited UNITED STATES PATENTS 11/1963 McCormick 22044 6/1968 Miller 22044 GEORGE T. HALL, Primary Examiner US. Cl. X.R. 

